Determining if a file is locked in Windows

[elake]

I found this thread about a pst file in Windows being locked and I am
having the same issue.

http://groups.google.com/group/comp.lang.python/browse_thread/thread/d3dee5550b6d3652/ed00977acf62484f?lnk=gst&q=%27copying+locked+files%27&rnum=1

The problem is that I have a script that can find the pst files on
every machine in my network and back them up to a server for safe
keeping. The problem is that when Outlook is running it locks the file
and will not allow me to copy it to the destination. I am using the
shutil module for the copy.

Is there a way to first determine if the file is locked and then do the
copy if it isn't? I thought about looking to see if Outlook.exe is
running but the machines are shared and the process could be running
but with a different pst file in use.

Thanks in advance